Blood smear from a patient with the microgranular variant of acute promyelocytic leukemia (APL; formerly described in the French-American-British [FAB] classification as M3V). The promyelocytes vary in size and degree of cytoplasmic basophilia. The cytoplasm contains abundant, fine, azurophilic granules and the nuclei are markedly lobulated and invaginated. (Wright-Giemsa stain)
From Brunning RD, McKenna RW. Tumors of the bone marrow. Atlas of tumor pathology (electronic fascicle), Third series, fascicle 9, 1994, Washington, DC. Armed Forces Institute of Pathology.